The fleet manager should make his way to the top of the GM food chain and explain to them the kind of money your company is spending with them and that will all go away when they turn back the leases and go get some Ford Escapes or Honda CRVs...if they care about the business in the least they will fix the vehicles at no charge...The only bulletin I found was related to a noisey pump/injectors stating that this was a normal condition...uh yeah, right????
Keep your eyes peeled for bulletins in the next year or so, GM may reimburse after the fact.
With customer service like this, we should have let them go out of business...